Respiratory syncytial infection (RSV) is a major cause of morbidity for infants during the first year of life, especially among premature infants or infants with bronchopulmonary dysplasia (BPD). MEDI-493 is a humanized monoclonal antibody directed toward the fusion protein in RSV. This is a Phase III, placebo-controlled study to 1) further establish the safety of monthly MEDI-493 IM injections in the above infants; 2) determine the efficacy of prophylaxis with MEDI-493 with regard to hospitalizations in these infants. This center enrolled 12 patients into the study. All of the patients successfully completed the study. None of the infants enrolled required hospitalization for an RSV infection, and only two were hospitalized for a respiratory illness (not RSV related). The results of this multi-center study were published in a press release in July 1997. Initial analysis of results suggests that MEDI-493 reduced the incidence of RSV-associated hospitalizations by fifty-five percent. MedImmune expects to submit a Biologic License Application to the FDA requesting marketing approval of MEDI-493. Data are subject to further analysis by the company and full review by regulatory authorities before a definitive assessment of the safety and efficacy of MEDI-493 can be made.